Imaging apparatus and method of controlling imaging apparatus

ABSTRACT

An imaging apparatus includes a first calculation unit configured to calculate angular velocity of an object to the imaging apparatus, based on a detection result of a first detection unit that detects a motion vector of the object based on temporally-continuous images obtained by an image sensor and a detection result of a second detection unit that detects motion of the imaging apparatus, a second calculation unit configured to calculate angular acceleration of the object to the imaging apparatus, based on a plurality of angular velocities calculated by the first calculation unit, and a correction unit configured to move a correction component based on the angular velocity of the object to the imaging apparatus during exposure by the image sensor, and to correct image blur of the object.

BACKGROUND Field of the Disclosure

The present disclosure relates to correction of image blur occurred inso-called follow shot imaging.

Description of the Related Art

In the related art, follow shot imaging has been known as imagingtechnique expressing a sense of speed of a moving object. In the followshot imaging, a camera is panned by a photographer according to movementof the object, to cause the moving object to stop and to cause abackground to flow. In the follow shot imaging, it is necessary for thephotographer to pan the camera according to the movement of the object.If the panning speed is extremely high or low, difference occurs betweenthe moving speed of the object and the panning speed, which may oftencause blur object image.

Accordingly, in Japanese Patent. Application Laid-Open No. H4-163535, apart of an optical system of a lens or an imaging unit during exposureis moved based on relative angular velocity of the object to the imagingapparatus calculated before exposure and angular velocity of the imagingapparatus during exposure obtained from an angular velocity sensor,thereby correcting blur of the object (object blur). In addition, inJapanese Patent Application Laid-Open No. H4-163535, the relativeangular velocity of the object the imaging apparatus is calculated froma moving amount of the object on an image plane detected fromtemporally-continuous images and an output of the angular velocitysensor.

In the technique discussed in Japanese Patent Application Laid-Open. No.H4-163535, however, the movement of the object is detected and the blurcorrection is performed; however, an error of the moving amount of theobject on the image plane detected from the temporally-continuous imagesis not considered. To detect the moving amount of the object on theimage plane from the temporally-continuous images, there a method ofseparating an object region and a background region with use of theoutput of the angular velocity sensor, and detecting a motion vector ofthe object region between the continuous images to detect the movingamount of the object on the image plane. In the method, in a case wherethe camera is slowly panned, it is difficult to separate the objectregion and the background region and to obtain the moving amount of theobject on the image plane with high accuracy from the continuous images.Accordingly, the calculated relative angular velocity of the object tothe imaging apparatus is shifted from the actual relative angularvelocity, and the blur correction of the object is not performed withhigh accuracy in some cases.

SUMMARY

According to an aspect of the present disclosure, an imaging apparatuscapable of performing a follow shot, includes at least one processor,the at least one processor functioning, according to a program stored ina memory, as a first detection unit configured to detect a motion vectorof an object, based on temporally-continuous images obtained by an imagesensor, a second detection unit configured to detect motion of theimaging apparatus, a first calculation unit configured to calculateangular velocity of the object to the imaging apparatus, based on adetection result of the first detection unit and a detection result ofthe second detection unit, a second calculation unit configured tocalculate angular acceleration of the object to the imaging apparatus,based on a plurality of angular velocities calculated by the firstcalculation unit, and a correction unit configured to move a correctioncomponent based on the angular velocity of the object to the imagingapparatus during exposure by the image sensor, and to correct image blurof the object. The correction unit changes, according to the detectionresult of the second detection unit, a degree of a calculation result ofthe second calculation unit reflected when the angular velocity of theobject to the imaging apparatus during exposure by the image sensor usedin control of the correction component is determined.

Further features of the present disclosure will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating processing of determining objectangular velocity during exposure according to one or more aspects of thepresent disclosure.

FIG. 2 is diagram illustrating imaging processing in a follow shotassisting mode according to one or more aspects of the presentdisclosure.

FIG. 3 is a diagram illustrating a configuration of a camera accordingto one or more aspects of the present disclosure.

FIG. 4 is a diagram illustrating a configuration of an imagestabilization system according to one or more aspects of the presentdisclosure.

FIG. 5 is a diagram illustrating panning control according to one ormore aspects of the present disclosure.

FIG. 6 is a diagram illustrating a configuration of a driving controlsystem of a shift lens in the follow shot assisting mode according toone or more aspects of the present disclosure.

FIG. 7 is a diagram illustrating an angular velocity data in panning.

FIG. 8 is a diagram illustrating a relationship between relative angularvelocity and angular acceleration of an object.

FIG. 9 is a diagram to explain the relative angular velocity of theobject.

FIG. 10 is a diagram illustrating processing of correcting objectangular acceleration according to one or more aspects of the presentdisclosure.

FIG. 11 is a diagram illustrating processing of determining objectangular velocity during exposure according to one or more aspects of thepresent disclosure.

DESCRIPTION OF THE EMBODIMENTS

Some exemplary embodiments of the present disclosure will be describedbelow with reference to drawings.

FIG. 3 is a block diagram illustrating a configuration of alens-integrated camera as an imaging apparatus according to a firstexemplary embodiment of the present disclosure. A camera 100 includes animaging lens unit 101 that is an imaging optical system focusing lightfrom an object. The imaging lens unit 101 includes a main lens 102, azoom lens 103 that can change a focal length, and an unillustrated focuslens that performs focus adjustment. Further, the imaging lens unit 101includes a shift lens 104 that moves in a direction orthogonal to anoptical axis to optically correct blur of an object image. In the followshot imaging in which a user images a moving object while changing adirection of the camera 100 through panning, the shift lens 104 ismovable (shiftable) in the direction orthogonal to the optical axis toassist the follow shot for reduction of blur of the object image. Themain lens, the zoom lens, the focus lens, and the shift lens included inthe imaging lens unit 101 each include one or more lenses. Further, thecamera 100 includes a zoom encoder 105 that detects a position of thezoom lens 103, a position sensor 106 that detects a position of theshift lens 104, and an angular velocity sensor 107 that detects movementof the imaging apparatus, such as a gyro sensor. Further, the camera 100includes an amplifier 108 that amplifies an output of the angularvelocity sensor 107, a microcomputer 130 for camera control, a driver109 that drives the shift lens 104, and an amplifier 110 that amplifiesan output of the position sensor 106.

The camera 100 further includes a shutter 111, an image sensor 112, ananalog signal processing circuit 113, a camera signal processing circuit114, a timing generator 115, an operation switch 116, a shutter drivingmotor 117, and a driver 118.

The image sensor 112 includes a photoelectric conversion device such asa complementary metal-oxide semiconductor (CMOS) sensor or acharge-coupled device (CCD) sensor, and photoelectrically converts theobject image formed by the imaging lens unit 101 to output an analogelectric signal. The shutter 111 controls an exposure time of the imagesensor 112.

The analog signal processing circuit (analog front end (AFE)) 113amplifies the analog signal output from the image sensor 112, furtherconverts the amplified analog signal into a digital imaging signal, andprovides the imaging signal to the camera signal processing circuit 114.

The camera signal processing circuit 114 performs various kinds of imageprocessing on the imaging signal to generate an image signal (picked-upimage). The picked-up image (or still image taken out therefrom) isrecorded in a memory card 119 that is detachable from the camera 100, oris displayed on a monitor (hereinafter, liquid crystal display (LCD))120 that includes a display device such as a liquid crystal panel.Moreover, the camera signal processing circuit 114 includes a motionvector detection unit 135 that detects a motion vector between frameimages configuring the image signal.

The timing generator 115 sets operation timing of the image sensor 112and the analog signal processing circuit 113. The operation switch 116includes various kinds of switches such as a power switch, a releaseswitch, and a mode selection switch, and a dial. In the camera 100according to the present exemplary embodiment, a follow shot assistingmode and a normal imaging mode are switchable through operation of themode selection switch. The shutter driving motor 117 is driven by thedriver 118 to charge the shutter 111.

Further, the microcomputer 130 includes an image stabilization controlunit 131, a follow shot control unit 132, a shutter control unit 133,and an object angular velocity calculation unit 134.

The image stabilization control unit 131 performs camera-shakecorrection control (image stabilization control) in which driving of theshift lens 104 is controlled in order to correct (reduce) blur of theobject image caused by camera shake.

The follow shot control unit 132 controls the shift driving of the shiftlens 104 to assist the follow shot.

The shutter control unit 133 releases energization of an unillustratedrelease electromagnetic magnet through the driver 118 to open theshutter 111 in a charged state, and controls the shutter driving motor117 to perform charging operation of the shutter 111.

The object angular velocity calculation unit 134 calculates relativeobject angular velocity of the object to be imaged, to the camera 100.In addition, the microcomputer 130 performs, for example, focus lenscontrol and diaphragm control.

For the camera-shake correction, detection and correction are performedin terms of two orthogonal axes such as a horizontal direction and avertical direction; however, only one axis is described in the presentexemplary embodiment because of the same configuration in the two axes.

When the power switch of the operation switch 116 is operated and thecamera 100 turned on, the microcomputer 130 detects the status change,and power supply and initial setting to each of the circuits in thecamera 100 are performed.

In the normal imaging mode in which the follow shot assisting mode isnot set, the angular velocity sensor 107 detects shake of the camera 100due to hand shake, and the image stabilization control unit 131 uses aresult of the detection and drives the shift lens 104 to performcamera-shake correction.

A camera-shake correction function is now described. FIG. 4 is a diagramillustrating a configuration of the image stabilization system accordingto the present exemplary embodiment. Components similar to thecomponents in FIG. 3 are denoted by the same reference numerals, anddescription of the components is omitted. In FIG. 4, reference numerals401 to 407 illustrate detailed components of the image stabilizationcontrol unit 131. An analog-to-digital (A/D) converter 401 converts ananalog signal as an angular velocity signal output from the angularvelocity sensor 107 (amplifier 108), into a digital signal as angularvelocity data. Output data sampling of the angular velocity sensor 107is performed with a frequency of about 1 kHz to about 10 kHz.

A filter calculation unit 402 includes, for example, a high-pass filter(HPF), and reduces an offset component included in the angular velocitydata and changes a cutoff frequency of the HPF. A first integrator 403converts the angular velocity data into angular displacement data inorder to generate driving target data of the shift lens 104. An A/Dconverter 406 converts an analog signal as a position signal of theposition sensor 106, into a digital signal as position data. A firstadder 404 subtracts a current shift lens position from the drivingtarget value of the shift lens 104 to calculate a driving amount data ofthe shift lens 104. A pulse-width modulation (PWM) output unit 405provides the calculated driving amount data to the shift lens drivingdriver 109.

A panning control unit 407 determines whether the camera 100 has beenpanned, from the angular velocity data. Further, in a case where it isdetermined as panning, the panning control unit 407 performs cutofffrequency change control of the filter calculation unit 402 andadjustment of an output of the first integrator 403.

FIG. 5 is a diagram illustrating an example of a flowchart of thepanning control performed by the panning control unit 407.

In step S501, the panning control unit 407 determines whether an averagevalue (average value by predetermined number of times of sampling,hereinafter, referred to as angular velocity average value) of theangular velocity data taken from the A/D converter 401 is larger than apredetermined value α. In a case where the angular velocity averagevalue is equal to or lower than the predetermined value α (NO in stepS501), the panning control unit 407 determines that the panning is notperformed, and the processing proceeds to step S507. In contrast, in acase where the angular velocity average value is larger than thepredetermined value α (YES in step S501), the processing proceeds tostep S502 and the panning control unit 407 determines whether theangular velocity average value is larger than a predetermined value β.In a case where the angular velocity average value is equal to or lowerthan the predetermined value β (No in step S502), the panning controlunit 407 determines that slow panning (at low speed) is performed, andthe processing proceeds to step S506. In a case where the angularvelocity average value is larger than the predetermined β (YES in stepS502), the panning control unit 407 determines that drastic panning (athigh speed) is performed, and the processing proceeds to step S503.

The panning control unit 407 sets the cutoff frequency of the HPF in thefilter calculation unit 402 to a maximum value in step S503, andforcibly turns off the camera-shake correction control (in non-executionstate) in step S504. The reason why the image stabilization control isturned off in the high-speed panning is because, if the high-speedpanning is handled as large camera shake and the shift lens 104 isshifted, the picked-up image is largely moved at a time when the shiftlens 104 reaches a shift end, which gives unpleasant sensation to aphotographer. In addition, this because, in the case where thehigh-speed panning is performed, the movement of the picked-up image bythe panning is, large, and appearance of the image blur caused by camerashake hardly gives unpleasant sensation to the photographer. Moreover,the shift lens 104 is gradually stopped in next step after the cutofffrequency of the HPF is set to the maximum value, which makes itpossible to avoid giving unpleasant sensation to the photographer due toappearance of image blur caused by camera shake according to theturning-off of the image stabilization control.

Thereafter, in step S505, the panning control unit 407 gradually changesthe output of the first integrator 403 from the current data to data atan initial position, which gradually returns the shift lens 104 to theinitial position. This is because the shift lens 104 is desirably placedat the initial position within the driving range at a time whencamera-shake correction operation is restarted.

In step S506, the panning control unit 407 sets the cutoff frequency ofthe HPF according to the size of the angular velocity data value. Thisis because image blur caused by camera shake is conspicuous in thelow-speed panning, and therefore it is necessary to correct the imageblur. The cutoff frequency is set such that the image blur caused bycamera shake is corrected while followability of the picked-up image tothe panning is maintained at a degree not causing unnaturalness.

In step S507, the panning control unit 407 sets the cutoff frequency ofthe HPF to a value in normal times.

In step S508, the panning control unit 407 releases the forcible offsetting of the image stabilization control (turns on image stabilizationcontrol).

FIG. 7 is a diagram illustrating a relationship between the angularvelocity data in the horizontal direction in the panning and both of thepredetermined values α and β. A reference numeral 701 in FIG. 7 denotessampled angular velocity data. In this example, the angular velocitydata in a plus direction is obtained in a case where the camera 100 ispanned rightward, and the angular velocity data in a minus direction isobtained in a case where the camera 100 is panned leftward. In theexample of FIG. 7, drastic (high-speed) right panning and slow(low-speed) right and left panning are detected.

As illustrated in FIG. 7, the angular velocity data is largely deviatedfrom an initial value (zero in this case) in the panning. Therefore, ina case where the angular velocity data is integrated to calculate thetarget position data of the shift lens 104, the output of the firstintegrator 403 becomes an extremely-large value due to a direct-current(DC) offset component, which results in an uncontrollable state.Accordingly, in the case where the panning is detected, it is necessaryto increase the cutoff frequency of the HPF to cut the DC component.This is particularly remarkable in the case of the drastic panning, andtherefore the cutoff frequency is further increased to prevent theoutput of the first integrator 403 from being increased. In the case ofthe drastic panning, the movement of the image by the panning becomesextremely large with respect to the camera shake. Therefore, even if thecamera-shake correction function is turned off in the panning direction,unpleasant sensation does not particularly occur.

The panning control is performed in the above-described manner, whichmakes it possible to obtain the image without pleasant sensation in thepanning.

In FIG. 3, when the follow shot assisting mode is set through theoperation switch 116, the motion vector detection unit 135 of the camerasignal processing circuit 114 detects a motion vector of the object fromthe picked-up image. The detected motion vector is provided for thefollow shot control unit 132. Further, at the same time, the follow shotcontrol unit 132 receives the angular velocity data from the angularvelocity sensor 107 (amplifier 108).

When the photographer performs the follow shot, the motion vector of theobject output from the motion vector' detection unit 135 includes twokinds of vectors, a vector corresponding to a main object to bepicked-up by the photographer and a vector corresponding to a flowingbackground. At this time, out of the two kinds of detected motionvectors, data with a small moving amount becomes the motion vector ofthe main object, and a value of the motion vector represents a movingamount of the main object on an image plane because this is intended forthe follow shot.

In contrast, the angular velocity data corresponds to the panning speed(follow shot speed) of the camera 100. Therefore, a difference betweenthe angular velocity data and the angular velocity that is calculatedfrom the moving amount of the main object on the image plane and thecurrent focal distance of the lens, is calculated, to obtain the angularvelocity of the main object to the camera 100. The object angularvelocity calculation unit 134 calculates the angular velocity of themain object to the camera 100 (also referred to as relative objectangular velocity) at every timing when the monitor image is processed.Further, the object angular velocity calculation unit 134 transmits, tothe follow shot control unit 132, set information about the calculatedrelative object angular velocity and the calculated calculation time(acquisition time).

FIG. 6 is a diagram illustrating a configuration of a driving controlsystem of the shift lens 104 in the follow shot assisting mode, andcomponents similar to those in FIG. 3 and FIG. 4 are denoted by the samereference numerals. A camera information acquisition unit 601 acquiresfollow shot setting information indicating that the follow shotassisting mode has been set through operation of the mode selectionswitch of the operation switch 116, and release information indicatingthat the imaging has been instructed through operation of the releaseswitch. An angular velocity data output unit 602 samples the angularvelocity data at predetermined timing and provides the sampled angularvelocity data for the object angular velocity calculation unit 134.

An object angular velocity determination unit 603 acquires the setinformation about the relative object angular velocity and thecalculation time thereof that have been calculated by the object angularvelocity calculation unit 134 before imaging for recording (beforeexposure of image sensor 12 for still image recording), and holds(accumulates) the set information as an angular velocity history. In thefollowing description, exposure indicates imaging for recording.Further, the object angular velocity determination unit 603 determinesthe relative object angular velocity that is predicted angular velocity(predicted information) of the object to the camera 100 during theexposure period (in imaging), through, for example, calculation with useof the angular velocity history before the exposure (before exposureperiod). As a result, the object angular velocity determination unit 603determines the acquired relative object angular velocity during theexposure period, as the relative object angular velocity to be used incontrol of the shift driving of the shift lens 104 during the exposureperiod in the follow shot assisting.

A second adder 604 calculates a difference between the angular velocitydata from the angular velocity sensor 107 and the relative objectangular velocity during the exposure period that has been determined bythe object angular velocity determination unit 603. A second integrator605 performs integration operation only during the exposure period. Asetting change unit 606 changes setting of the panning control unit 407,according to notification of the setting information about the followshot assisting mode from the camera information acquisition unit 601.

When the follow shot assisting' mode is set through operation of theoperation switch 116, the camera information acquisition unit 601notifies the setting change unit 606 of the follow shot settinginformation. The setting change unit 606 performs the setting change ofthe panning control unit 407, according to the notified follow shotsetting information. The setting change performed at this time is tofacilitate transition to the drastic panning state. More specifically,the above-described predetermined values β and α for panningdetermination are changed.

In addition, the second adder 604 calculates a difference between theangular velocity data from the angular velocity sensor 107 and therelative object angular velocity from the object angular velocitydetermination unit 603, and transmits a result of the calculation to thesecond integrator 605.

The second integrator 605 starts the above-described integrationoperation of the differences during the exposure period, according tothe release information from the camera information acquisition unit601. The second integrator 605 outputs a value at which the position ofthe shift lens 104 becomes the initial position (center) during a periodother than the exposure period. In a case where the shift lens 104 isintended to be placed at the center position during the period otherthan the exposure period, the shift lens 104 suddenly moves from thecurrent position to the center position at the end of the exposureperiod. A time period immediately after the exposure period, however,corresponds to a time period during which the image signal is read outfrom the image sensor 112. Thus, during the time period, display of thepicked-up image is not performed on the LCD 120. Therefore, movement ofthe picked-up image due to sudden movement of the shift lens 104 causesno problem.

Further, the output of the second integrator 605 is added to the outputof the first integrator 403 by the first adder 404, and the shiftposition data of the shift lens 104 provided from the position sensor106 (shift position A/D converter 406) is subtracted from the addedvalue. As a result, driving amount data of the shift lens 104 iscalculated.

When the follow shot operation with high-speed panning is actuallyperformed by the photographer in the follow shot assisting mode, thepanning control unit 407 immediately starts the panning control andturns off the image stabilization control as described in step S504 inFIG. 5. In the panning control, the shift lens 104 is moved to correct adisplacement amount of the object image on the image plane thatcorresponds to the difference between the angular velocity by thepanning of the camera 100 and the relative object angular velocity asthe angular velocity of the main object (hereinafter, simply referred toas object) to the camera 100. Accordingly, the difference between thepanning speed of the camera 100 and the moving speed of the objectduring the exposure period that is a cause of follow shot failure, iscanceled by the shift driving of the shift lens 104. As a result, thefollow shot succeeds.

The object angular velocity determination unit 603 determines therelative object angular velocity during the exposure period with use ofthe angular velocity history that has been acquired from the objectangular velocity calculation unit 134 and accumulated before theexposure, in consideration of the time of a release time lag and theexposure period. For example, in a case where the follow shot of anobject performing uniform linear motion is performed by the camera 100that is positioned in a direction orthogonal to a traveling direction ofthe object, the angular velocity of the object measured by the camera100 is continuously varied. Therefore, the angular velocity of theobject is not the same between at the time of being detected and duringthe exposure period. Therefore, it is necessary to consider thevariation of the angular velocity, i.e., acceleration, in order tofavorably perform the above-described correction by the shift driving ofthe shift lens 104.

FIG. 8 is a diagram illustrating a relationship between the relativeangular velocity and the angular acceleration of the object, andillustrates variation of the angular velocity when the angular velocityof the object (train) performing uniform linear motion is measured bythe camera 100 that is positioned in a direction orthogonal to atraveling direction of the object, as illustrated in FIG. 9. In FIG. 9,the object performs the uniform linear motion at speed v from left toright. A point A is a position (hereinafter, referred to as origin) atwhich a distance from the camera 100 on a moving trajectory in theuniform linear motion of the object becomes the shortest. A length L isa distance from the camera 100 to the origin A (the shortest distance tomoving trajectory). An angle θ is formed by the direction from thecamera 100 to the origin A, i.e., the direction orthogonal to thetraveling direction of the object and the direction from the camera 100to the object (i.e., direction of camera 100; hereinafter, referred toas panning angle), and has a plus value on the right side of the originA and has a minus value on the left side thereof.

A horizontal axis in FIG. 8 indicates the panning angle θ and a centervertical axis indicates the angular velocity of the object. When theobject in FIG. 9 is positioned at the origin A, the panning angle θbecomes 0 degrees. A graph of a solid line indicates the variation ofthe angular velocity. Further, a right vertical axis indicates theangular acceleration, and a graph of a dashed line indicates thevariation of the angular acceleration. The variation of the angularacceleration used herein is variation of the angular acceleration of theobject corresponding to the position of the object based on the positionof the camera. FIG. 8 illustrates the angular velocity and the angularacceleration in a case where the shortest distance from the camera 100to the origin A is 20 m, and the object performs the uniform linearmotion at speed of 60 km/h.

In FIG. 8, the angular velocity becomes the maximum and the angularacceleration becomes zero at a time when the object passes through theorigin A (panning angle θ is 0 degrees). Further, the angularacceleration becomes the maximum when the panning angle θ is +30degrees, and the angular acceleration becomes the minimum when thepanning angle θ is −30 degrees. The relationship between the panningangle θ and both of the angular velocity and the angular acceleration isnot depend on the shortest distance and the velocity of the objectdescribed above.

FIG. 2 is a diagram illustrating a flowchart of the imaging processingin the follow shot assisting mode. The processing is performed by themicrocomputer 130 according to a follow shot assisting control programthat is a computer program.

In step S201, the microcomputer 130 determines whether the releaseswitch has been half-pressed (whether SW1 is ON). In a case where therelease switch has been half-pressed (SW1 is ON; YES in step S201), theprocessing proceeds to step S202, and a time measurement counter isincremented. In a case where the release switch has not beenhalf-pressed (SW1 is not ON; NO in step S201), the processing proceedsto step S203, and the time measurement counter is reset. The processingthen returns to step S201.

In step S204, the microcomputer 130 confirms whether the relative objectangular velocity (simply referred to as object angular velocity in FIG.2) has been already calculated by the object angular velocitycalculation unit 134. In a case where the relative object angularvelocity has been already calculated (YES in step S204), the processingproceeds to step S205, and the microcomputer 130 confirms whether a timeof the time measurement counter has reached a predetermined time T. In acase where the relative object angular velocity has not yet beencalculated (NO in step S204) and in a case where the relative objectangular velocity has been already calculated but the time of the timemeasurement counter has reached the predetermined time T (the exposureperiod is longer than the predetermined time T; YES in step S205), theprocessing proceeds to step S206.

In step S206, the microcomputer 130 causes the object angular velocitycalculation unit 134 to calculate the relative object angular velocity.This causes the object angular velocity calculation unit 134 tocalculate the relative object angular velocity and causes the objectangular velocity determination unit 603 to acquire the angular velocityhistory, before the exposure that is started in response to full-pressoperation of the release switch, which will be described below. Thereason why the relative object angular velocity is calculated again inthe case where the time of the time measurement counter has reached thepredetermined time T is to consider possibility of variation of thevelocity of the object in the predetermined time T. The relative objectangular velocity calculated by the object angular velocity calculationunit 134 is transmitted to the object angular velocity determinationunit 603 at every calculation. In case where the time of the timemeasurement counter has not yet reached the predetermined time T in stepS205 (NO in step S205), the processing proceeds to step S208.

In step S207 after step S206, the microcomputer 130 causes the objectangular velocity determination unit 603 to determine the relative objectangular velocity during the exposure period. The process will bedescribed in detail below. The processing then proceeds to step S208.

In step 3208, the microcomputer 130 determines whether the releaseswitch has been fully pressed (whether SW2 is ON). In a case where therelease switch has not been fully pressed (SW2 is not ON; NO in stepS208), the processing returns to step S201. In contrast, in a case wherethe release switch has been fully pressed (SW2 is ON; YES in step S208),the processing proceeds to step S209, and the microcomputer 130 opensthe shutter 111 through the shutter control unit 133, thereby startingexposure.

Further, in step S210, the microcomputer 130 causes the follow shotcontrol unit 132 to perform the driving control of the shift lens 104according to the relative object angular velocity determined in stepS207. As a result, the follow shot assisting to correct the displacementamount of the object image on the image plane is performed. At thistime, in a case where the panning is determined as the high-speedpanning in step S502 in FIG. 5, the microcomputer 130 drives the shiftlens 104 through the image stabilization control unit 131 in order tocorrect image blur caused by camera shake.

Subsequently, in step S211, the microcomputer 130 determines whether theexposure has been completed. In a case where the exposure has beencompleted (YES in step S211), the processing proceeds to step S212. In acase where the exposure has not been completed (NO in step S211), theprocessing returns to step S210. In step S212, the microcomputer 130determines whether the release switch has been fully pressed (whetherSW2 is ON) again. In a case where the release switch has been fullypressed (SW2 is ON; YES in step S212), the processing returns to stepS209, and next exposure (imaging of next frame in continuous imaging) isperformed. In contrast, in a case where the release switch has not beenfully pressed (SW2 is not ON; NO step S212), the processing returns tostep S201.

FIG. 1 is a diagram illustrating a flowchart of the processing ofdetermining the object angular velocity during exposure that isperformed by the object angular velocity determination unit 603 in stepS207 in FIG. 2, The processing is performed by the object angularvelocity determination unit 603 according to the follow shot assistingcontrol program that is a computer program, and the processing isstarted when the object angular velocity determination unit 603 receivesnotification of the object angular velocity in step S206.

In step S101, the object angular velocity determination unit 603acquires the latest angular velocity data, and the processing thenproceeds to step S102. In step S102, the object angular velocitydetermination unit 603 performs threshold determination with respect toan X-axis direction (first direction) of the held latest angularvelocity data. In the present exemplary embodiment, the X-axis directionindicates a direction orthogonal to a gravity direction, and as with inFIG. 7, the angular velocity data in the pleas direction is obtained inthe case where the camera 100 is panned rightward, and the angularvelocity data in the minus direction is obtained in the case where thecamera 100 is panned leftward. A Y-axis direction described belowindicates a direction parallel to the gravity direction, and the angularvelocity data in the plus direction is obtained in a case where thecamera 100 is panned upward, and the angular velocity data in the minusdirection is obtained in a case where the camera 100 is panned downward.In a case where an absolute value of the angular velocity data in theX-axis direction is larger than a first threshold (e.g., 6 dps) (YES instep S102), the processing proceeds to step S103. In a case where theabsolute value of the angular velocity data in the X-axis direction isequal to or lower than the first threshold (NO in step S102), theprocessing proceeds to step S106.

In step S103, the object angular velocity determination unit 603performs threshold determination with respect to the Y-axis direction(second direction orthogonal to first direction) of the latest angularvelocity data. In a case where an absolute value of the angular velocitydata in the Y-axis direction is larger than the first threshold (e.g., 6dps) (YES in step S103), the processing proceeds to step S104. In a casewhere the absolute value of the angular velocity data in the Y-axisdirection is equal to or lower than the first threshold (NO in stepS103), the processing proceeds to step S105.

In step S104, the object angular velocity determination unit 603calculates, for each of the X-axis direction and the Y-axis direction,the object angular acceleration during exposure, based on a plurality ofheld past relative object angular velocities. Further, the objectangular velocity determination unit 603 calculates the angular velocitydifference during exposure from the release time lag and the calculatedobject angular acceleration, and adds the angular velocity difference tothe relative object angular velocity calculated in step S206, therebypredicting the relative object angular velocity during exposure. Aresult of the prediction is determined as the relative object angularvelocity during exposure, and the processing of determining the angularvelocity then ends.

In step S105, the object angular velocity determination unit 603determines, for the Y-axis direction, the relative object angularvelocity calculated in step S206, as the relative object angularvelocity during exposure. In contrast, the object angular velocitydetermination unit 603 calculates, for the X-axis direction, the objectangular acceleration during exposure, based on the plurality of heldpast relative object angular velocities. Further, the object angularvelocity determination unit 603 calculates the angular velocitydifference during exposure from the release time lag and the calculatedobject angular acceleration, and adds the angular velocity difference tothe relative object angular velocity calculated in step S206, therebypredicting the relative object angular velocity during exposure. Aresult of the prediction is determined as the relative object angularvelocity during exposure, and the processing of determining the angularvelocity then ends.

In step S106, the object angular velocity determination unit 603performs threshold determination with respect to the Y-axis direction ofthe latest angular velocity data. In the case where the absolute valueof the angular velocity data in the Y-axis direction is larger than thefirst threshold (e.g., 6 dps) (YES in step S106), the processingproceeds to step S107. In the case where the absolute value of theangular velocity data in the Y-axis direction is equal to or lower thanthe first threshold (NO in step S106), the processing proceeds to stepS108.

In step S107, the object angular velocity determination unit 603determines, for the X-axis direction, the relative object angularvelocity calculated in step S206, as the relative object angularvelocity during exposure. In contrast, the object angular velocitydetermination unit 603 calculates, for the Y-axis direction, the objectangular acceleration during exposure, based on the plurality of heldpast relative object angular velocities. Further, the object angularvelocity determination unit 603 calculates the angular velocitydifference during exposure from the release time lag and the calculatedobject angular acceleration, and adds the angular velocity difference tothe relative object angular velocity calculated in step S206, therebypredicting the relative object angular velocity during exposure. Aresult of the prediction is determined as the relative object angularvelocity during exposure, and the processing of determining the angularvelocity then ends.

In step S108, the object angular velocity determination unit 603determines, for each of the X-axis direction and the Y-axis direction,the relative object angular velocity calculated in step S206, as therelative object angular velocity during exposure.

As described above, when the absolute value of the angular velocity dataof the camera 100 is larger than the threshold, the angular accelerationis calculated based on the previous relative object angular velocity,and variation of the relative object angular velocity until exposure ispredicted with use of the calculation result of the angularacceleration. In other words, the variation of the relative objectangular velocity until exposure predicted based on the previous relativeobject angular velocity, to predict the relative object angular velocityduring exposure. In contrast, when the absolute value of the angularvelocity data of the camera 100 is equal to or lower than the threshold,the variation of the relative object angular velocity until exposure isnot predicted based on the previous relative object angular velocity. Inother words, the angular acceleration is not calculated based on theprevious relative object angular velocity, and the relative objectangular velocity during exposure is determined without reflecting aresult of the calculation. This is because, when the variation of therelative object angular velocity is predicted in the case where theabsolute value of the angular velocity data of the camera 100 is equalto or lower than the threshold, the variation of the relative objectangular velocity is not predicted with high accuracy in some cases dueto the error of the moving amount of the object on the image planedetected from the temporally-continuous images.

Accordingly, the above-described control makes it possible to suppressinfluence of the error of the moving amount of the object on the imageplane detected from the temporally-continuous images and to performcamera shake correction.

In the present exemplary embodiment, the first threshold is 6 dps as anexample; however, the threshold may be appropriately set inconsideration of the influence of the error of the moving amount of theobject on the image plane detected from the temporally-continuousimages.

A second exemplary embodiment will be described. In the first exemplaryembodiment, the variation of the relative object angular velocity untilexposure is predicted based on the angular acceleration when theabsolute value of the angular velocity data of the camera 100 is largerthan the threshold, and the variation of the relative object angularvelocity until exposure is not predicted when the absolute value of theangular velocity data of the camera 100 is not larger than thethreshold. In contrast, in the second exemplary embodiment, a method ofpredicting the variation of the relative object angular velocity ischanged in a stepwise manner according to the absolute value of theangular velocity data of the camera 100. This makes it possible toperform more favorable image blur correction according to the movementof the camera 100. More specifically, in the case were the variation ofthe relative object angular velocity until exposure is not predictedbased on the previous relative object angular velocity in the firstexemplary embodiment (steps S105, S107, and S108 in FIG. 1), comparisonof the threshold and the angular velocity data (processing illustratedin FIG. 10) is further performed.

FIG. 10 is a diagram illustrating a flowchart of processing ofcorrecting the object angular acceleration that is performed in stepsS105, S107, and S108 in FIG. 1. The configuration of the imagingapparatus and the processing other than the processing illustrated inFIG. 10 according to the present exemplary embodiment are similar tothose in the first exemplary embodiment, and detailed descriptionthereof is accordingly omitted.

In a case where the processing proceeds to step S105, S107, or S108according to the flowchart in FIG. 1, the object angular velocitydetermination unit 603 performs a process in step S109 for, as a target,the angular velocity data, the absolution value of which is not largerthan the first threshold, out of the angular velocity data in the X-axisdirection and the Y-axis direction.

In step S109, the object angular velocity determination unit 603determines whether the absolute value of the target angular velocitydata is larger than a second threshold (smaller than first threshold,e.g., 3 dps). In a case where the absolute value of the target angularvelocity data is not larger than the second threshold (NO in step S109),the processing proceeds to step S110. In a case where the absolute valueof the target angular velocity data is larger than the second threshold(YES in step S109), the processing proceeds to step S111. As for thedirection, the angular velocity data of which is not a target, theobject angular acceleration during exposure is calculated based on theplurality of held past relative object angular velocities. Further, theobject angular velocity determination unit 603 calculates the angularvelocity difference during exposure from the release time lag and thecalculated object angular acceleration, and adds the angular velocitydifference to the relative object angular velocity calculated in stepS206, thereby predicting the relative object angular velocity duringexposure. A result of the prediction is determined as the relativeobject angular velocity during exposure.

In step S110, as for the direction, the angular velocity data of whichis a target, the object angular velocity determination unit 603determines the relative object angular velocity calculated in step S206,as the relative object angular velocity during exposure. Morespecifically, the object angular velocity determination unit 603 regardsthe object angular acceleration until exposure as zero, and determinesthe relative object angular velocity during exposure without reflectingthe calculation result of the angular acceleration.

In step S111, as for the direction, the angular velocity data of whichis a target, the object angular velocity determination 603 calculatesthe object angular acceleration during exposure, based on the pluralityof held past relative object angular velocities. Further, the objectangular velocity determination unit 603 calculates the angular velocitydifference during exposure from the release time lag and the objectangular acceleration that is ½ of the calculated object angularacceleration, and adds the angular velocity difference to the relativeobject angular velocity calculated in step S206, thereby predicting therelative object angular velocity during exposure. A result of theprediction is determined as the relative object angular velocity duringexposure.

As described above, in the present exemplary embodiment, the degree ofthe object angular acceleration until exposure that is reflected whenthe relative object angular velocity during exposure is determined isdecreased in a stepwise manner as the angular velocity data value isdecreased. As a result, it is possible to reduce difference of therelative object angular velocity during exposure between the case wherethe angular velocity data value is larger than the threshold and thecase where the angular velocity data value is lower than the threshold,which makes it possible to perform more favorable image blur correctionaccording to the movement of the camera 100 as compared with the firstexemplary embodiment.

Although the first threshold is 6 dps as an example and the secondthreshold is 3 dps as an example in the present exemplary embodiment,the thresholds are not limited as long as the first threshold is smallerthan the second threshold. Further, the first threshold in the presentexemplary embodiment is set to the value similar to that in the firstexemplary embodiment; however, the first threshold may be set to avalue, e.g., 12 dps, larger than that of the first exemplary embodimentin order to perform stepwise control.

Moreover, in the case where the angular velocity data has a valuebetween the first threshold and the second threshold, the object angularacceleration that is ½ of the object angular acceleration calculatedbased on the past relative object angular velocity is used. The ratio ofthe object angular acceleration to be reflected, however, is not limitedto ½, and may be any ratio smaller than one.

Furthermore, in the present exemplary embodiment, the angular velocitydata is compared with the two thresholds, and the stepwise control isperformed; however, the angular velocity data may be compared with threeor more thresholds and the stepwise control may be performed.Alternatively, a table in which the angular velocity data is associatedwith the ratio of the object angular acceleration until exposure that isreflected when the relative object angular velocity during exposure isdetermined, may be stored in a memory in the microcomputer 130, and thestepwise control may be performed based on the table.

Further, in the first and second exemplary embodiments, the angularacceleration is not calculated and is regarded as zero, and the relativeobject angular velocity during exposure is determined without reflectingthe calculation result of the angular acceleration. Alternatively, theangular acceleration may be calculated but the relative object angularvelocity during exposure may be determined without reflecting thecalculation result of the angular acceleration at all.

In addition, in the first and second exemplary embodiments, the methodof determining the relative object angular velocity during exposure ischanged based on comparison between the angular velocity data and thethresholds. Alternatively, a method of determining the relative objectangular velocity during exposure may be changed based on comparisonbetween the object angular acceleration calculated with use of theangular velocity data and the thresholds.

A third exemplary embodiment is described. FIG. 11 is a diagramillustrating a flowchart of the processing of determining the objectangular velocity during exposure that is performed by the object angularvelocity determination unit 603 in step S207 in FIG. 2, according to thethird exemplary embodiment. The processing is performed by the objectangular velocity determination unit 603 according to the follow shotassisting control program that is a computer program, and the processingis started when the object angular velocity determination unit 603receives notification of the object angular velocity in step S206.

In step S1101, the object angular velocity determination unit 603 readsout the angular velocity history ω(n−p) to ω(n) (plurality of angularvelocities) before exposure that has been calculated and accumulated bythe object angular velocity calculation unit 134. The latest objectangular velocity ω(n) is calculated in step S206 in FIG. 2, where n isequal to or larger than three and p is equal to or larger than one.

In step S1102, the object angular velocity determination unit 603calculates angular acceleration α(n) that is the displacement amount perunit time, from the read angular velocity history ω(n−p) to ω(n), forexample, with use of a least-squares method.

In step S1103, the object angular velocity determination unit 603calculates (predicts), from the previously-calculated angularacceleration α(n−1), an angular velocity ωexpect(n) that expected at acalculation time of the object angular velocity ω(n).

In step S1104, the object angular velocity determination unit 603calculates, from the calculated angular velocity ωexpect(n), a valuerange (range of possible value) A(α(n)) of the angular accelerationα(n).

A method of calculating the value range A(α(n)) is described withreference to FIG. 9. A reference symbol v denotes the object speed, areference symbol L denotes the shortest distance between the movingtrajectory of the object and the camera, and a reference symbol tdenotes a moving time from a point of the object to a point at which thedistance between the moving trajectory of the object and the camerabecomes the shortest.

The angular velocity ω of the object is a time differential of thepanning angle θ and is expressed by the following expression,

$\begin{matrix}{\omega = \frac{d\; \theta}{dt}} & \left( {{Numerical}\mspace{14mu} {expression}\mspace{14mu} 1} \right)\end{matrix}$

and the following expression is established from FIG. 9.

$\begin{matrix}{{\tan \; \theta} = {\left. \frac{vt}{L}\leftrightarrow\theta \right. = {{\tan^{- 1}\left( \frac{vt}{L} \right)}\mspace{14mu} \left( {{{- 90}{^\circ}} < \theta < {90{^\circ}}} \right)}}} & \left( {{Numerical}\mspace{14mu} {expression}\mspace{14mu} 2} \right)\end{matrix}$

At this time, when the following expression is established,

$\begin{matrix}{u_{1} = \frac{vt}{L}} & \left( {{Numerical}\mspace{14mu} {expression}\mspace{14mu} 3} \right)\end{matrix}$

the numerical expression 1 is modified to the following expression.

$\begin{matrix}{\omega = {\frac{d\; \theta}{dt} = {{\frac{d\; \theta}{{du}_{1}} \cdot \frac{{du}_{1}}{dt}} = {{\left( \frac{1}{1 + u_{1}^{2}} \right) \cdot \left( \frac{v}{L} \right)} = \frac{Lv}{L^{2} + ({vt})^{2}}}}}} & \left( {{Numerical}\mspace{14mu} {expression}\mspace{14mu} 4} \right)\end{matrix}$

Further, the angular acceleration α of the object is a time differentialof the angular velocity ω and is expressed by the following expression.

$\begin{matrix}{\alpha = \frac{d\; \omega}{dt}} & \left( {{Numerical}\mspace{14mu} {expression}\mspace{14mu} 5} \right)\end{matrix}$

At this time, when the following expression is established,

u ₂ =L ²+(vt)²   (Numerical expression 6)

the numerical expression 5 is modified to the following expression.

$\begin{matrix}{\alpha = {\frac{d\; \omega}{dt} = {{\frac{d\; \omega}{{du}_{2}} \cdot \frac{{du}_{2}}{dt}} = {{\left( \frac{- {Lv}}{u_{2}^{2}} \right) \cdot \left( {2v^{2}t} \right)} = \frac{{- 2}{Lv}^{3}t}{\left( {L^{2} + ({vt})^{2}} \right)^{2}}}}}} & \left( {{Numerical}\mspace{14mu} {expression}\mspace{14mu} 7} \right)\end{matrix}$

When the angular acceleration α is expressed by an expression of theangular velocity ω, the following expression is established.

$\begin{matrix}{\alpha = {\frac{{- 2}{Lv}^{3}t}{\left( {L^{2} + ({vt})^{2}} \right)^{2}} = {{\left( \frac{Lv}{L^{2} + ({vt})^{2}} \right)^{2} \cdot \left( \frac{{- 2}v}{L} \right) \cdot t} = {\omega^{2} \cdot \left( \frac{{- 2}v}{L} \right) \cdot t}}}} & \left( {{Numerical}\mspace{14mu} {expression}\mspace{14mu} 8} \right)\end{matrix}$

Further, when the angular acceleration α is expressed by an expressionof the angular velocity ω and the panning angle θ with use of thenumerical expression 2, the following expression is established.

$\begin{matrix}{\alpha = {{\omega^{2} \cdot \left( \frac{{- 2}v}{L} \right) \cdot \left( {\frac{L}{v}\tan \; \theta} \right)} = {{- 2}\omega^{2}\tan \; \theta}}} & \left( {{Numerical}\mspace{14mu} {expression}\mspace{14mu} 9} \right)\end{matrix}$

At this time, as illustrated in FIG. 8, the angular acceleration becomesthe minimum when the panning angle θ is −30 degrees, and the angularacceleration becomes the maximum when the panning angle θ is +30degrees, and ωexpect(n) is the angular velocity at each angle.Accordingly, the angular acceleration α(n) is inevitably included in thevalue range A(α(n)) expressed by the following expression.

$\begin{matrix}{{{- \frac{2}{\sqrt{3}}}\left( {\omega_{expect}(n)} \right)^{2}} \leq {\alpha (n)} \leq {\frac{2}{\sqrt{3}}\left( {\omega_{expect}(n)} \right)^{2}}} & \left( {{Numerical}\mspace{14mu} {expression}\mspace{14mu} 10} \right)\end{matrix}$

Alternatively, when a domain of the panning angle θ is determined, thevalue range A(α(n)) is more detailed.

In step S1105, the object angular velocity determination unit 603determines whether the angular acceleration α(n) is included in thevalue range A(α(n)). In a case where the angular acceleration α(n) isincluded in the value range A(α(n)) (YES in step S1105), the processingproceeds to step S1106, and otherwise (NO in step S1105), the processingproceeds to step S1107.

In step S1107, the object angular velocity determination unit 603determines whether the difference between the angular acceleration α(n)and the value range A(α(n)) is equal to or larger than a threshold. Whenthe difference is equal to or larger than the threshold (YES in stepS1107), the processing proceeds to step S1108, and otherwise (NO in stepS1107), the processing proceeds to step S1109.

In step S1108, the object angular velocity determination unit 603 setsthe value of the angular acceleration α(n) to zero. This is synonymouswith stoppage of the determination (prediction) of the object angularvelocity in step S1106 described below. After the angular accelerationα(n) is set, the processing proceeds to step S1106.

In step S1109, the object angular velocity determination unit 603 setsthe value of the angular acceleration α(n) to a close value from amongthe maximum value and the minimum value of the value range A(α(n)).After the angular acceleration α(n) is set, the processing proceeds tostep S1106.

In step S1108, the object angular velocity determination unit 603 setsthe value of the angular acceleration α(n) to zero. Alternatively, theobject angular velocity determination unit 603 may simply set the valueof the angular acceleration α(n) to any exceptional value, and cause thefollow shot control unit 132 to determine the exceptional value in stepS210 in FIG. 2, thereby stopping the follow shot assisting.Alternatively, a step of determining whether the number of times inwhich the angular acceleration α(n) is not included in the value range A(α(n)) is equal to or larger than a second threshold, may be newlyprovided. When the number of times is equal to or larger than the secondthreshold, any exceptional value stopping the follow shot assisting maybe set.

In step S1106, the object angular velocity determination unit 603 usesthe angular acceleration α(n) to determine (predict) the object angularvelocity.

As described above, according to the present exemplary embodiment, theobject angular velocity predicted in consideration of the value range ofthe angular acceleration, which makes it possible to suppress influenceof the error of the moving amount of the object on the image planedetected from the temporally-continuous images and to correct blur ofthe object.

Further, in the first to third exemplary embodiments, the example of thelens-integrated camera has been described; however, the camera may be alens interchangeable camera and an angular velocity sensor provided inan interchangeable lens may be used.

Moreover, in the first to third exemplary embodiments, the example inthe case where the follow shot assisting mode is set according to theoperation by the user has been described; however, the camera maydetermine movement of the camera, and automatically make a transition tothe follow shot assisting mode.

Further, in the first to third exemplary embodiments, the example inwhich the shift lens is used as the correction component to correct thedifference between the moving speed of the object and the panning speed,has been described. Alternatively, an image sensor may be used as thecorrection component, and the image sensor may be moved to correct thedifference between the moving speed of the object and the panning speed.

Other Embodiments

Embodiment (s) of the present disclosure can also be realized by acomputer of a system or apparatus that reads out and executes computerexecutable instructions (e.g., one or more programs) recorded on astorage medium (which may also be referred to more fully as a‘non-transitory computer-readable storage medium’) to perform thefunctions of one or more of the above-described embodiment(s) and/orthat includes one or more circuits (e.g., application specificintegrated circuit (ASIC)) for performing the functions of one or moreof the above-described embodiment(s), and by a method performed by thecomputer of the system or apparatus by, for example, reading out andexecuting the computer executable instructions from the storage mediumto perform the functions of one or more of the above-describedembodiment(s) and/or controlling the one or more circuits to perform thefunctions of one or more of the above-described embodiment(s). Thecomputer may comprise one or more processors (e.g., central processingunit (CPU), micro processing unit (MPU)) and may include a network ofseparate computers or separate processors to read out and execute thecomputer executable instructions. The computer executable instructionsmay be provided to the computer, for example, from a network or thestorage medium. The storage medium may include, for example, one or moreof a hard disk, a random-access memory (RAM), a read only memory (ROM),a storage of distributed computing systems, an optical disk (such as acompact. disc (CD), digital versatile disc (DVD), or Blu-ray Disc(BD)™), a flash memory device, a memory card, and the like.

While the present disclosure has been described with reference toexemplary embodiments, the scope of the following claims are to beaccorded the broadest interpretation so as to encompass all suchmodifications and equivalent structures and functions.

This application claims the benefit of Japanese Patent Applications No.2017-125530, filed Jun. 27, 2017, and No. 2017-219344, filed Nov. 14,2017, which are hereby incorporated by reference herein in theirentirety.

What is claimed is:
 1. An imaging apparatus capable of performing afollow shot, the imaging apparatus comprising: at least one processor,the at least one processor functioning, according to a program stored ina memory, as a first detection unit configured to detect a motion vectorof an object, based on temporally-continuous images obtained by an imagesensor; a second detection unit configured to detect motion of theimaging apparatus; a first calculation unit configured to calculateangular velocity of the object to the imaging apparatus, based on adetection result of the first detection unit and a detection result ofthe second detection unit; a second calculation unit configured tocalculate angular acceleration of the object to the imaging apparatus,based on a plurality of angular velocities calculated by the firstcalculation unit; and a correction unit configured to move a correctioncomponent based on the angular velocity of the object to the imagingapparatus during exposure by the image sensor, and to correct image blurof the object, wherein the correction unit changes, according to thedetection result of the second detection unit, a degree of a calculationresult of the second calculation unit reflected when the angularvelocity of the object to the imaging apparatus during exposure by theimage sensor used in control of the correction component is determined.2. The imaging apparatus according to claim 1, wherein the seconddetection unit detects angular velocity data of the imaging apparatus,and wherein the correction unit changes the degree of the calculationresult of the second calculation unit according to a value of theangular velocity data detected by the second detection unit.
 3. Theimaging apparatus according to claim 2, wherein, in a case where anabsolute value of the angular velocity data detected by the seconddetection unit is equal to or lower than a first threshold, thecorrection unit determines the angular velocity of the object to theimaging apparatus during exposure by the imaging apparatus used in thecontrol of the correction component, without reflecting the calculationresult of the second calculation unit.
 4. The imaging apparatusaccording to claim 3, wherein, in a case where the absolute value of theangular velocity data detected by the second detection unit is largerthan the first threshold, the correction unit determines the angularvelocity of the object to the imaging apparatus during exposure by theimage sensor used in the control of the correction component, based on acalculation result of the first calculation unit and the calculationresult of the second calculation unit.
 5. The imaging apparatusaccording to claim 2, wherein the correction unit changes the degree ofthe calculation result of the calculation unit in a stepwise manneraccording to the value of the angular velocity data detected by thesecond detection unit.
 6. The imaging apparatus according to claim 1,wherein the correction unit changes angular acceleration that is used todetermine the angular velocity of the object to the imaging apparatusduring exposure by the image sensor, according to whether the angularacceleration calculated by the second calculation unit is includedwithin a value range corresponding to the angular velocity calculated bythe first calculation unit.
 7. The imaging apparatus according to claim6, wherein the correction unit uses the angular acceleration calculatedby the second calculation unit to determine the angular velocity of theobject to the imaging apparatus during exposure in a case where theangular acceleration calculated by the second calculation unit isincluded in the value range, and the correction unit uses angularacceleration set to a predetermined value, to determine the angularvelocity of the object to the imaging apparatus during exposure in acase where the angular acceleration calculated by the second calculationunit is not included in the value range.
 8. The imaging apparatusaccording to claim 7, wherein, in the case where the angularacceleration calculated by the second calculation unit is not includedin the value range, the correction unit determines the predeterminedvalue, based on at least one of a difference between the angularacceleration calculated by he second calculation unit and the valuerange, and a number of times the angular acceleration calculated by thesecond calculation unit is not included in the value range.
 9. Theimaging apparatus according to claim 8, wherein the correction unitdetermines the predetermined value to a value included in the valuerange.
 10. The imaging apparatus according to claim 6, wherein thecorrection it calculates the value range based on at least one of anangle, the angular velocity, the angular acceleration, and a distance ofthe object to the imaging apparatus, speed of the object, and a movingtime of the object.
 11. The imaging apparatus according to claim 1,wherein the correction component is the image sensor.
 12. The imagingapparatus according to claim 1, wherein the correction component is alens.
 13. A method of controlling an imaging apparatus capable ofperforming a follow shot, the method comprising: performing firstdetection to detect motion vector of an object, based ontemporally-continuous images obtained by an image sensor; performingsecond detection to detect motion of the imaging apparatus; performingfirst calculation to calculate angular velocity of the object to theimaging apparatus, based on a detection result of the first detectionand a detection result of the second detection; performing secondcalculation to calculate angular acceleration of the object to theimaging apparatus, based on a plurality of angular velocities calculatedin the first calculation; and moving a correction component based on theangular velocity of the object to the imaging apparatus during exposureby the image sensor, and correcting image blur of the object, wherein,in the correcting, a degree of a calculation result of the secondcalculation that is reflected when the angular velocity of the object tothe imaging apparatus during exposure by the image sensor used incontrol of the correction component is determined, is changed accordingto the detection result of the second detection.